The invention relates to a machine for the processing of foodstuffs or for the preparation of liquid or pasty pharmaceutical and chemical products. More particularly, the invention relates to a machine with a bowl, through the bottom of which bowl there leads a motor shaft, protruding perpendicularly into the bowl, of a motor arranged underneath the bowl, and with a shaft seal which seals off the motor shaft vacuum-tightly from the bowl bottom.
Such an embodiment can be taken from U.S. Pat. No. 3,612,546. Here, the shaft seal consists of two lip seals arranged one after the other and a cover plate fixed on the inside of the bowl wall, the two lip seals being fitted into the cover plate, which is designed as a sealing flange and is screwed with a neck bearing an external thread into the bowl wall. The two lip seals consist of a cap-type gasket and a retaining ring, which are seated in the neck of the sealing flange and form a constructional unit with the latter. The cap-type gasket lies with its cap rim against the shoulder of a ring fixed by press fitting in the neck of the sealing flange and is held in this position by the retaining ring pressed into the ring. The sealing flange is screwed with its neck into a threaded ring, which penetrates the bowl wall and bears against the latter from outside with a shoulder.